Progressive suspensions



Sepf- 11, 1956 E. c. BULLOCK PROGRESSIVE sUsPENsloNs 3 Sheets-Sheei l Filed June 9, 1955 O mm. Nm. .Wm .vm Om N V INVENTOR. E EAQLE g. BULL-00K TTOQNEY mm mmv ms m L omA SePt- 11, 1956 E. c. BuLLocK PROGRESSIVE sUsPENsloNs 3 sheeissheet 2 Filed June 9, 1955 mw S #m mm @m 2 mm INVENTOR. EARLE C: BU I LocK ATTORNEY sept l1, 1956 E. c. BULLOCK PROGRESSIVE susPENsloNs 3 Sheets-Sheet 3 Filed June 9, 1953 FIG/IO 44N INVENTOR. EAQLE' C Bu I LocK ATTOQNEY United States Patent Ofi ice 2,762,660 Patented Sept. 1l, 1956 PROGRESSIVE SUSPENSIONS Earle C. Bullock, Grand Rapids, Mich., assignor to Metal Olice Furniture Company,-Grand Rapids, Mich., 'a corporation of Michigan Appiication June 9, 1953, Serial No. 360,573

10 Claims. (Cl. 30S-3.8)

This invention relates to progressive suspensions and more particularly to the design of the channel sections and the arrangement of the balls within the channel sections forming the progressive suspensions.

Progressive suspensions normally consist of three major elements: the case rail, the suspension rail and the drawer rail. Each of these elements includes one or more channel sections. Heretofore, the component channel sections of each of these elements have been of different cross-section and shape, necessitating as a minimum, three different channels for each progressive suspension. The use of multiple shapes results in substantially higher tool and die costs as well as higher assembly and other fabricating cost.

This diiculty is eliminated by my invention since it provides a progressive suspension in which all three elements are formed by the use of four channel sections, each of identical shape and size. Thus, all of the channel sections forming these elements may be cut from a single, rolled shape. The use of a .single rolled shape effects substantial tool cost reduction and operating economy since the down-time required for changing a rolling machine from one shape to another is substantial.

Not only does my invention result in substantial manufacturing economies, it produces a superior suspension, one vcapable of resistingside-thrust from either direction. ln asuspension constructed according to my present invention, each separate suspension is capable of restraining side-thrust in either direction. In the suspension disclosed in my co-pending patent application entitled Expansible Drawer Supports, Serial No. 312,531, filed October l, 1952, each suspension is capable of restraining sidethrust in one direction only. Therefore, it was necessary to rely upon a pair of suspensions, one on each side of the drawento prevent side-racking of the drawer. In the case of the present invention, each individual suspension resists all side-thrust.

Other objects of my invention include the production of a progressive suspension capable ofoperating quietly, easily and with a minimum of wear.

These and other objects and purposes of my invention will be immediately seen by those acquainted withthe design and construction of progressive suspensions upon reading the following speciiication and the accompanying drawings.

In the drawings:

Fig. l is a side elevation view of the inside face of my improved progressive suspension showing `the suspension in extended position.

Fig. 2 is a fragmentary sectional elevation view taken along the plane II-ll of Fig. showing the suspension in extended position.

Fig. 3 is a side elevation view of the inside face of my invention showing the progressive suspension in closed position.

Fig. 4 is a .fragmentary sectional-elevation view taken 2 along the plane II--II of Fig. 7 showing the suspension in closed position.

Fig. 5 is a sectional elevation View taken along the plane V-V of Fig. 3. n

Fig. 6 is a sectional elevation view taken along the plane VI-VI of Fig. 3.

Fig. 7 is a sectional elevation view taken along the plane VII-VII of Fig. 3.

Fig. 8 is a sectional elevation view taken along the plane VIII-VIII of Fig. 3.

Fig. 9 is an end elevation view of the channel Vsection used in my invention.

Fig. 10 is a fragmentary, enlarged planvview of one form of stop used in my invention.

Fig. l1 is a side elevation view ofthe stop appearing in Fig. l0.

Fig. l2 is an enlarged, fragmentary plan view of the support for the back endof my suspension.

Fig. 13 is an enlarged, fragmentary side elevation view of the support for the back end of my suspension.

Briey described, my invention utilizes a generally C- shaped channel having its free ends flanged with both flanges extending in the same direction and parallel to the main web of the channel. One length of channel is used for the case rail and one for the drawer rail, the drawer rail being inverted with respect to the case rail. The suspension rail consists of a pair of channel sections, one being inverted with respect to the other so that the legs of the'channels, adjacent the inturned free end, are in abutting relationship. The abutting legs are rigidly welded together to form the rail. The case and drawer rails are telescopically received into the suspension rail, one in each channel of the suspension rail. The three rails are separated from each other and supported one upon the other by means of ball bearings seated in raceways formed between the channels. The channels are so designed that these raceways are square, permitting the balls to contact the top and bottom and both side surfaces of the raceways. Thus, relative movement of the rails with respect one to the other is prevented not only vertically but laterally, the only relative displacement permitted being longitudinal. A disk-shaped propulsion roller is seated in a slot at the center of the suspension rail. The top surface of the roller bears against the drawer rail and the lower surface of the roller bears against theicase rail. The roller transmits a substantial portion of the load from the drawer rail to the case rail. It also serves as a propulsion member assuring proportional movement of each of the rails as the suspension is extended and retracted.

In the following description the terms forward and rearward are frequently used and are to be taken .to mean forward toward the left in Figs. l, 2, 3 and 4 and rearward away therefrom. The terms front and back 'as used herein are synonymous with forward and rearward respectively.

Referring to the drawingsin greater detail, the numerical 10 indicates a case rail upon which is mounted a suspension rail 11 which in turn suspends a drawer rail '12. Each of these rails consists of lengths of channel section of identical cross-sectional size and shape,

The channel section 13 is generally C-shaped, having va pair of parallel arms 14 and 15 connected by a web V16 (Fig. 9). At the end of the arms 14 and 15, remote from theweb 16, are a pair of ilanges 17 and 18. These flanges extend in the same direction and are parallel to the web 16. Since the flanges 17 and 18 extend in the same direction, one of them extends inwardly and Vthe other outwardly of the channel. The outwardly extending ange 18 is off-set slightly from the inturned flange 17 whereby it is somewhat closer to the web 16.

3 Thedrawer rail 12 and case rail 10 each consist of a single length of the channel713. The channel of the drawer rail 12 is inverted withl respect to the channel of lthe case rail whereby the outwardly extending flanges of both rails extend toward each other. 'Ihe suspension rail 11 consists of an upper channel 20 and a lower channel 21 (Figs. 5, 6, 7 and 8). The upper channel is inverted with respect to the lower channel 21 so that the legs 14 of both channels abut each other. Where the legs 14 are in contact, they are secured together at 22 to form a rigid unit. As the structure appears in Fig. 5, the upper channel 20 is inverted with respect to the drawer rail 12. The channel 21 is inverted with respect to the case rail 10.

The lower portion of the drawer rail 12 is telescopically received within the upper portion, i. e., the channel 2t) of the suspension rail 11. The upper portion of the case rail- 10 is telescopically received within the lower por tion, i. e., the channel 21 of the suspension rail 11. The telescoping of these rails produces six raceways. These raceways include the two outer raceways 23 and 24, the two intermediate raceways and 26, and the two inner raceways 27 and 28 (Figs. 5, 6, 7 and 8). A pair of balls are seated within each of the outer raceways 23 and 24 and the intermediate raceways 25 and 26. The balls of each pair are separated a distance approximately equal to one-half of the length of the suspension. Only one ball is utilized in each of the inner raceways 27 and 28. The inner and outer raceways are each of identical size. The intermediate raceways are substantially larger in crosssection. All of the raceways have a square crosssection making their height and width equal within approximately 0.015 of an inch. The importance of this will be described later.

A narrow, rectangular opening is provided through the center of the suspension rail 11. This opening extends through the channels 20 and 21 where they are vjoined together to form the suspension rail 11. Seated within this opening is a propulsion roller 30. The propulsion roller 30 is generally disk-shaped and has a diameter equal to the combined heights of the inner race vways 27 and 28 plus the thickness of the case rail 11 where the channels 20 and 21 are joined. The upper 'portion of the roller 30 bears against the lower leg of the drawer rail 12 and the lower portion of the roller 30 bears against the upper leg of the case rail 10. 'I'he propulsion roller 30 'has no axle and is not attached to n the suspension rail 11 except to the extent that its forward and rearward motion relative to the suspension rail is limited by the ends of the opening within which it is seated.

In the following description of the relationship of the balls within the raceways, the suspension assembly is assumed to be in closed position. The forward balls 31, 32, 33 and 34 (Fig. 6), seated in the upper and lower, outer raceways and the upper and lower, intermediate raceways respectively, are substantially vertically aligned, and spaced forwardly from the propulsion roller 30 approximately one-fourth of the length of the suspension. The rearward balls 35, 36, 37 and 38 (Fig. S), seated in the upper and lower, outer raceways and the upper and lower, intermediate raceways respectively are substantially vertically aligned and spaced rearwardly from the propulsion roller 30 approximately one-fourth of the length of the suspension. rPhe ball 39 seated in the upper, inner raceway 27 is forward of the propulsion roller 30 and substantially vertically aligned with the forward balls 31, 32, 33 and 34 (Fig. 6). The ball 40 in the lower, inner raceway 28 is rearward of the propulsion roller 30 and substantially vertically aligned with the rearward balls 35, 36, 37 and 38 (Fig. 8).

Stops are provided on each of the rails to limit the zmovement of the balls as the suspension is extended and retracted. Two basic types of stops are utilized. One type of stop consists of either an L-shaped angle or a 4 block secured to the rail either by a screw or by weldlng. The other type is formed by cutting or nicking the rail and then bending the metal on one side of the cut to form a somewhat triangularly shaped Wing 45 extending into the raceway (Figs. 10 and ll). The latter type stop 44 is used to limit the movement of the smaller balls 31, 32, 35, 36, 39 and 40. The L-shaped angle or block type of stop is used to limit the movement of the larger balls 33, 34, 37 and 38.

The stop 50 is mounted at the forward end of the suspension rail 1l and together with the stop 51, mounted substantially at the center of the drawer rail 12, controls the movement of the ball 33 (Figs. l and 2). The stop 52 on the suspension rail 11 and the stop 53 at the rearward end of the drawer rail 12, limit movement of the rearward ball 37. The stop 54, mounted on the forward end of the case rail 10 and the stop 55 mounted adjacent the center of the suspension rail 11, limit the movement of the forward hall 34. The stop 56, mounted adjacent the center of the case rail 10 and the stop 57 mounted at the rearward end of the suspension rail 11, limit the movement of the rearward ball 38.

Only those of the stops 44 are shown which are not hidden when the suspension is viewed from the inside. It will be understood, however, that two stops 44 are provided for each of the balls 31, 32, 35, 36, 39 and 40. Further illustration and description of these stops is not considered necessary, inasmuch as the use of stops and their relationship to the balls is conventional in suspensions of this type.

The suspension is secured to the case, both at the front and back ends of the case rail 10. At the forward end, a shoulder rivet 60 (Figs. 3, 4 and 5) is secured to the case channel. The rivet 60 is designed to seat within a keyhole-shaped slot in the case frame. This rigidly secures the forward end of the suspension since in operation there is no tendency for the suspension to rise 'and become disengaged from the case.

At the rearward end, a L-shaped plate 61 having a rear flange 62 and a bottom ilange 63, is secured to the case rail 10 by means of a pair of screws 64 and 65 (Figs. 9 and l0). The rearward flange 62 mounts a pair of resilient stops 66. The finger 67, integral with the plate 61, is designed to pass through an aperture in the bracket 68. The bracket 68 is secured to the case 69.

The various components of my suspension are preferably fabricated from steel. The propulsion roller 30 may, if desired, be fabricated from a suitable, wear-resistant plastic.

Operation The case rail 10 remains stationary since it is secured to the supporting structure. As the suspension is extended, the drawer rail 12 moves a distance substantially equal to the length of the case rail 10. Simultaneously the suspension rail 11 moves one-half the distance of the drawer rail. During this movement the propulsion roller 30 acts as a major support for the drawer rail upon the 'case rail and serves to coordinate the movement of both the drawer rail and suspension rail. The movement of the propulsion roller 30 is equal to one-half the movement of the drawer rail.

The balls move forwardly with the drawer rail at a rate equal to one-fourth .that of the rail. Thus, when the suspension is fully extended, the Iballs 31, 33 and 39 vsupport the drawer rail substantially at its center upon the forward end of the suspension rail. The balls 36, 38 and 40 `anchor the back end of the suspension nail 11 to the case rail 10 substantially at the center `of the case rail 10. The balls 35 and 37 secure the back end of the drawer rail 12 to the suspension rail 11 immedi-ately yadjacent and 'slightly forward of the propulsion roller 30. At the same time, the balls 32 and 34 support `the suspen- Ssion rail 111 upon ythe case rail 10 adjacent to and slightly rearwardly of the propulsion roller 30.

Since these balls contact the sides as well as the top and bottom of their-raceways, they serve not onlyfto transmit vertical loads but also to transmit all side-thrust loads imposed upon the suspension. This eliminates lateral misaiignment of the suspension. Since the major loading imposed upon the balls is vertical, the balls track according `to their contact with the upper and lower surfaces of the raceways. Should, however, any one of the balls, due to :the imposition of eccentric loads, fail to move its full distance in the raceway, the stops will prevent the ball from becoming permanently mislocated in its raceway.

Since the balls are capable of taking lateral thrust loads in either direction, it is impossible to misalign the rails of this suspension. Thus, the rails automatically remain in alignment. This results in a substantial reduction in wear. Where the suspensions are used to support a drawer, it results in greatly facilitating the operation of the drawer since it maintains proper alignment and prevents any portion of the drawer striking the cabine-t.

The use of a single channel shape for all rails of the suspension results in substantial alignment, vertically, of the inside and outside surfaces of the suspension. lThis facilitates the mounting Iof a member such as a drawer between a pair of suspension assemblies -since there is no projection on the suspension to limit the vertical position of the drawer with respect to the center of the suspension. Thus, 'the drawer may be so mounted that a major portion of it projects above the suspension or it may be hung between the suspensions with a major portion of the drawer extending below `the suspension. This permits `the suspensions to be used for many dilereut purposes such as for ling cabinet drawers, desk drawers and any other use where a progressive suspension is desired. Although my suspension is primarily designed to mount drawers, it will be recognized that its purpose is not limited thereto.

While l have described a preferred embodiment of my invention, it will be recognized that various modiiications of my invention may be made, each without departing from the principle thereof. Each of these modl- 'lications is to be considered as included in the hereinafter appended claims, unless these claims by their language expressly state otherwise.

l claim:

l. In a progressive suspension, the combination comprising: four channel sections or" identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining channel sections being secured `together `to form a suspension rail; said drawer rail fbeing telescopically received into one channel section of said suspension ra-il; said case rail being telescopically received into the other channel section of said suspension rail.

2. In a progressive suspension, the combination cornprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming `a drawer rail, the remaining pair of channel sections being secured together to form a suspension rail; one channel section of said pair being linverted with respect `to and sea-ted one upon the other; said drawer rail being telescopically received into one channel section of said suspension rail; said case rail being telescopically received into the other channel section Iof said suspension rail.

3. In a progressive suspension, the combination comprising: four channel sect-ions of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail, the remaining pair of channel sections being secured together lto form a suspension rail; one channel section of said pair being inverted with respect `to and seated one upon the other; said case rail being inverted with respect to said drawer rail and both being telescopically received into said suspension rail.

4. In a progressive suspension, the combination comprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; `a second of said channel sections forming a drawer rail; the remaining channel sections being secured together to form a generally S-sh-aped suspension rail; anti-friction means lbetween each of said rails.

5. In a progressive suspension, the combination Vcomprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining channel sectionsbeing secured together to form a generally S-shaped suspension rail; said channel sections forming raceways of square cross-section between each of said rails; balls seated in each of said raceways for separating each of said rails both vertically and laterally.

6. In a progressive suspension, the combination comprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining channel sections being secured together to form a suspension rail; said channel sections forming two inner, two outer and two intermediate raceways of square cross-section between said rails; said two inner and two outer raceways being of the same size; said two intermediate raceways being larger than said inner and outer raceways; a ball seated in and adjacent each end of each of said outer and intermediate raceways; a ball seated in and adjacent one end of each of said inner raceways; said balls in said inner raceways being at opposite ends of said suspension; said balls each having a diameter equal to the width of the raceway within which they are seated.

7. In a progressive suspension, the combination comprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining channel sections being secured together to form a suspension rail; said channel sections forming two inner, two outer and two intermediate raceways of square cross-section between said rails; a ball seated in and adjacent each end of each of said outer and intermediate raceways; a ball seated in and adjacent one end of each of said inner raceways; said balls in said inner raceways being at opposite ends of said suspension; said balls each having a diameter equal to the width of the raceway within which it is seated; an opening through the center of said suspension rail; a propulsion roller extending through said opening and contacting both said drawer and case rails.

8. In a progressive suspension, the combination comprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining channel sections being secured together to form a generally S-shaped suspension rail; said channel sections forming raceways between said rails; each of said raceways having a maximum width equal to the maximum height thereof.

9. In a progressive suspension, the combination comprising: four channel sections of identical cross-section; one of said channel sections forming a case rail; a second of said channel sections forming a drawer rail; the remaining pair of channel sections being secured together to form a suspension rail; one channel section of said pair being inverted with respect to and seated upon the other; said channel sections forming raceways between said rails; each of said raceways having a maximum width equal to the maximum height thereof; balls seated in said raceways for holding said rails apart.

l0. In a progressive suspension having a case rail, a suspension rail and a drawer rail, said case rail and said drawer rail being telescopically received into said suspension rail, anti-friction means separating each of said rails from each adjacent rail, the improvement in said 2,519,623 Baker a Aug. 22, 1950 suspension comprising: said case rail and said drawer rail 2,574,162 Baker Nov. 6, 1951 each being comprised of one channel section; said suspension rail being comprised of a pair of channel sections; FOREIGN PATENTS said channel sections all being of identical cross-sectional 5 609,836 France Aug. 25, 1926 Shape- 659,534 Great Britain oct. 24, 1951 References Cited in the le of this patent v UNITED STATES PATENTS 1,109,812. Yawman Sept. 8, 1914 10 

